ANALYSIS OF OCCURRENCE CHARACTERISTICS AND SOURCE OF SWELL ON THE PACIFIC COAST

Abstract

 In this study, the occurrence characteristics of swell are investigated on the basis of a wave data set created by performing one year wave hindcasting for the Pacific Ocean using the wave model WAVEWATCH III. By applying a partitioning technique to the directional spectra of the data set, swell components are classified into the ones with short and long decay distances, respectively. As a result, it was found that the swell with short decay distance mainly comes from the southeast due to typhoons and low pressures, while the dominant swell with long decay distance comes from northeast, which originally developed in the northern North Pacific. Furthermore, we trace the swell by applying Wave System Tracking, and show the results of long period swell propagation to the Pacific coast of Japan, which originated from the South Pacific and the trade wind zone.